Many people who go to the doctor for the treatment of headaches are experiencing migraines, especially those with a history of minor neck injury. In the United States, it is estimated that over 20 million people suffer from migraines, which approximates the number of diabetics and asthmatic patients combined. Migraines occur in over 15% of women and over 5% of men. It has been estimated that direct and indirect costs of migraines in the United States exceeds $10B per year.
The occipital nerves tend to be an important part of the headache circuit that occasionally causes migraines. The occipital nerves are made up of a convergence of fibers from the first, second, and third cervical spinal nerves. These fibers form two sets of greater and lesser occipital nerves which loop outwards to control the muscles and sensation at the base of the skull and the scalp. These nerves run approximately one-half inch under the surface of the skin of a patient's head, on the upper neck and scalp. FIG. 1A is a side view of a patient's head 80 with paths 82 extending along the surface to depict the proximate locations under which the occipital nerves and branches 82a-c extend. FIG. 1B is a rear view of the patient's head 80 with the external occipital protuberance 92 resected and lifted on the right side 94. Various occipital nerve paths 90 are shown, including the greater occipital nerve path 90a and the lesser occipital nerve path 90b. 
A wide variety of medications are used to treat migraines, including long-activating preventative medications such as beta blockers and episodic migraine-reversers, such as tryptophan pain medications. In some cases, narcotics are used. However, many patients with migraines do not get satisfactory relief with medications. Some have tried the use of botulinum toxin (Botox) which may help relax the surrounding musculature and improve migraine symptoms in some patients. However, Botox and other medications are accompanied by a number of side effects that can be unpleasant to the patient.
In extreme cases, patients with intractable migraines historically have undergone surgical removal of occipital nerves. While this procedure has been known to provide transient relief (approximately 4-6 months), the headaches usually return in a more severe form that is unresponsive to other treatments.
More recent technological developments have included implantable occipital nerve stimulators. However, implantable nerve stimulators are complex, difficult to implement, and require surgical installation. Moreover, some existing topical stimulation systems do not provide sufficient control of the electrical current delivery, as stimulation current or voltage can vary depending on the pressure of the electrode applied to the skin. As a consequence, uneven and, in some cases, harmful stimulation can be applied.
Alternative systems and methods could be beneficial for the treatment of migraines.